Guide to New Zealand Ballast Water Controls
New Zealand has some of the most pristine seas in the world. Our unique marine environment is highly respected and enjoyed by all New Zealanders, and by many visitors from overseas.
However, New Zealand's territorial seas are under constant threat from unwanted foreign marine organisms carried on the hulls of ships and in ships' ballast tanks. Introduction of these organisms threatens our seafood industries, our environment and the health of our people.
Keeping our seas clean is very important, both culturally and economically to New Zealand.
We need your help to stop unwanted marine organisms entering New Zealand waters in, or on, vessels from overseas.
Ballast water discharge standard for New Zealand waters
New Zealand has rules controlling the discharge of ballast water spelled out in the Import Health Standard for Ballast Water.
Avoid delays and possible expense by complying with these rules. Unapproved discharge may result in the disruption of your voyage and possible legal proceedings.
Avoid unnecessary discharge
The safety and stability of your vessel are the only acceptable reasons for the discharge of unexchanged ballast water in New Zealand’s ports and territorial seas.
Discharging ballast in New Zealand ports and waters
Ballast water loaded in another country’s waters must not be discharged inside New Zealand territorial waters without permission.
Before arrival in New Zealand, a MPI Biosecurity Inspector will:
- grant permission if it has been shown that ballast was, or will, be exchanged adequately with mid-ocean water; or
- grant an exemption if it can be shown that an exchange of ballast water could not be undertaken safely in mid-ocean.
Note: emergency discharge is permitted. Ship and crew/passenger safety is paramount.
Log all ballast water management undertaken
You should record the volumes, locations and dates of all ballast water loaded, of exchanges undertaken and of discharges in New Zealand.
A MPI Biosecurity Inspector will ask to see this information. They may also want to talk with crew members about the loading and exchange of ballast water, and they may take ballast water samples for scientific testing.
Complete the Ballast Water Declaration
The two parts of the Ballast Water Declaration are available online at:
The electronic forms can be downloaded and customised with your vessel's details. Use your customised template every time you visit New Zealand waters. Complete the Declaration by entering details of ballast water management for the current voyage.
Before arrival, every ballasted vessel approaching New Zealand, that may need to discharge ballast water in New Zealand, must complete Part 1 and Part 2 (except for the discharges column). Copies of these are sent by fax or email, accompanying the Advance Notice of Arrival Form, to MPI Clearance Service via the ship’s agent in New Zealand.
Part 1 will be returned giving MPI's permission, if appropriate. You may discharge ballast once you have received this approval.
A MPI Biosecurity Inspector may ask to see the originals of both these forms when you come into port.
What about sediment in tanks?
Under no circumstances may sediment from the cleaning of holds, ballast tanks or anchor chain lockers be discharged into New Zealand's territorial waters. Sediment or mud can only be landed and disposed of at a landfill approved by an MPI Biosecurity Inspector.
Mid ocean exchanges
Mid ocean ballast water exchanges will reduce the chance of you introducing unwanted marine organisms to New Zealand waters.
Mid ocean ballast exchanges should be carried out with ocean water at least 200 nautical miles offshore.
Mid-ocean exchanges can be successfully carried out by using either the "empty-refill" method, or the "flow-through" method. If the "flow-through" method is used, three times the tanks' volume should be pumped through the tanks to ensure sufficient dilution of the coastal water. If using the empty-refill method you must replace at least 95% of the volume of water in the tank.
Other ways you can help
Minimise the uptake of harmful aquatic organisms by not loading ballast water in:
- Known high risk areas such as those listed above
- Very shallow water
- Locations where propellers may stir up sediment, or
- Locations where diseases such as cholera are known to be present in the water
Page last updated: 21 May 2013